1. Technical Field of the Invention
The present invention relates to power supply shutdown systems and, in particular, to a power supply shutdown apparatus adapted for use in a computer system.
2. Description of Related Art
Modularization is a much sought-after design paradigm in the field of computer systems. In personal computers, especially, modularization has resulted in a standardized motherboard having a processor unit, on-board memory, and a host of expansion slots into which are plugged various expansion cards providing such enhanced functionality as telecommunications, disk storage and improved video.
While modularization of stand-alone computers has resulted in standard features such as those described above, the fast-growing field of network computer systems has engendered a new level of modularization altogether. It has become increasingly clear to many computer designers that having a single motherboard with a system bus thereon in a computer that is networked in a server-client relationship with other computers (known as "clients") places severe design and performance constraints on that computer (known as a "server"). Many designers of server architectures have thus adopted a design philosophy of modularizing the motherboard itself into component system boards, all of which may be plugged into system board slots provided preferably on a backplane board having interconnect circuitry. Hence, it is envisioned in such a paradigm to have a backplane board with system board slots for, for example, a processor board containing at least a processor unit, various memory modules and possibly a few expansion slots for added functionality; and at least a port board containing a host of input/output ports.
It can be readily appreciated that modularization of a "motherboard" in a server into constituent system boards can result in increased serviceability and performance criteria. However, such "system-level" modularization is not without some drawbacks. One possible problem is that a user might inadvertently remove a system board while the server is still powered up. Because of the topography and lay-out of high-voltage bus traces in a high-performance bus system, such as, for example, a peripheral component interconnect ("PCI") bus system, any misalignment between a system board connector and the corresponding system board socket on the backplane will increase the probability of destroying some of the voltage-sensitive devices whose connectors are positioned near the high-voltage bus traces. A similar problem might also arise during the initial power up of the computer system when the modular system boards are not properly seated in the backplane board in the first place.
It is therefore advantageous to provide a power supply shutdown apparatus adapted for use in a computer having modularized system boards wherein when one of the system boards is misaligned, or missing, for any reason, the power supply to that system board is shut off. Although various current power supply shutdown systems have been extant for sometime, no such system is known to have all of the advantages and novel features of the system described, and claimed, hereinbelow.